Unloading crafts by new type of fluid operated pump

Acidizing and fracturing are the most common and effective reservoir stimulation methods.When the acidizing or fracturing treatment is completed,the timely flowback of reacted acid is a critical problem for the well stimulation,which will decrease the reservoir pollution by secondary precipitate of reacted acid.At the same time,there is great difficulty for collecting representative produced fluid samples as well as measuring formation pressure and deliverability while testing with TCP+DST for nonflow wells with low pressure and low permeability.Therefore,a new type of fluid operated pump was developed by drilling and production technology research institute of Dagang Oilfield,which could be applied for acidizing,fracturing and combination of perforation and testing.The successive forced unloading of this new type of pump could achieve good result in the above-mentioned operation.